A multilevel page table is preferred in comparison to a single-level p...
Single level page table is not preferred since it requires the number of page table entries to be equal to the number of virtual memory addresses, but a multi-level page table has smaller number of entries to reduce the size of page table needed.
A multilevel page table is preferred in comparison to a single-level p...
Understanding Multilevel Page Tables
Multilevel page tables are an efficient way to manage virtual to physical address translation in computer systems. Their primary advantage lies in memory efficiency.
Memory Efficiency
- Sparse Address Space: In many applications, virtual address spaces can be sparse, meaning not all addresses are used. A single-level page table would require a large contiguous block of memory, even for unused addresses.
- Hierarchical Structure: Multilevel page tables break the address space into smaller, manageable sections. Each level of the table can be created only as needed, which significantly reduces the amount of memory used.
Size Reduction
- Dynamic Allocation: With a multilevel structure, only the necessary portions of the page table are created. For example, if a process uses only a small portion of its virtual address space, only those entries in the page table are allocated.
- Scalability: As the size of processes and their address spaces grow, multilevel page tables can accommodate this growth without a linear increase in memory usage, making them more scalable compared to single-level page tables.
Conclusion
In summary, the main reason multilevel page tables are preferred over single-level page tables is their ability to reduce the overall size of the page table. This efficiency in memory usage allows for better management of virtual address spaces in processes, leading to optimized system performance.